Digital Terrain Models
A Digital Terrain Model (DTM) is a digital file consisting of terrain elevations
for ground positions at regularly spaced horizontal intervals. Digital terrain products
may be used to generate three-dimensional graphics displaying:
- Terrain slope
- Aspect (direction of slope)
- Terrain profiles between selected points
When used in combination with Digital Raster Graphics (DRGs), Digital Line Graphs
(DLGs), and digital orthorectified imagery, DTMs can create dramatic hybrid digital
images and enhance visual information for the purposes of data extraction and revision.
If your project calls for non-graphic applications, GeoEye's terrain modeling data
(gravity data) can be used for energy-resource searching, calculating the volume
of proposed reservoirs, and determining landslide probability. GeoEye is able to
produce digital terrain data anywhere in the world.